I want to know how chanting of mantra is helpful as per spiritual perspective? Is it better than meditation? Does it lead to any spiritual development or it is just another myth created by organised religions? Also, if it helps, which mantra we should chant daily for yielding maximum benefits? Is >
Chanting is not a replacement for meditation. IMO meditation is the single most important thing you can do to help with your spiritual progress. It clears the body, mind, and spirit of built up negative energy.
Chanting is used to reprogram the unconscious mind of some behavior you are doing automatically. Or to bring about some new kind of long term thought or belief. There is no one good or bad chant. You can even make up your own. The power in the chant is the repeated use of it. The unconscious mind is impervious to surface thoughts. It only responds to constant thought or action.
"I am healthy" for example will help you to fight sickness if you believe your are unwell and constantly draw it toward you in your life.
"I am loved" will help you to create more complete relationships if you believe you are not worthy of being loved.
Chanting is a wonderful tool for inner change but you have to be patience with it. It can take weeks or months to change beliefs that are deeply seated in your psyche.
So use both chanting and meditation.